1. Field of the Invention
The present invention relates to a measuring endoscope system that images an object to be inspected (object) and then measures the object to be inspected.
2. Description of the Related Art
In general, it is necessary to measure an object to be inspected (object) for the purpose of inspecting the detail of the object to be inspected (object).
When it comes to conventional endoscope systems, a measuring means that enables measurement of an object to be inspected (object) is needed for realization of endoscopic observation.
In order to meet the diverse demands, various proposals have been made of the measuring means for endoscopes, and disclosed in, for example, Japanese Unexamined Patent Application Publications Nos. 10-248806 and 60-237419 filed previously by the present applicant.
The former (Japanese Unexamined Patent Application Publication No. 10-248806) has disclosed a measuring endoscope system enabling stereoscopic (hereinafter stereo) measurement.
The latter (Japanese Unexamined Patent Application Publication No. 60-237419) has disclosed a length measuring optical adaptor for endoscopes that permits implementation of a comparison measurement technique. The comparison measurement technique is such that an index mark is projected on an object surface that is an object to be inspected (object), and compares an entity with the projected index mark for the purpose of measurement.
The measuring endoscope system described in the former Japanese Unexamined Patent Application Publication No. 10-248806 has an optical adaptor, which includes two optical systems needed to image an object to be inspected for the purpose of measurement, freely detachably attached to an endoscope body. The measuring endoscope system converges images, which are formed by two systems of lenses included in the optical adaptor, on one imaging device, processes at least the produced endoscopic image data, and performs measurement.
The measuring endoscope system includes a measuring means that performs reading, correction, coordinate transformation, and calculation. Specifically, the measuring means reads information from a recording medium on which optical data items concerning optical adaptors are recorded. Moreover, the measuring means corrects optical data according to an error in the position of an imaging module included in the endoscope body. Moreover, the measuring means performs coordinate transformation on images of an object to be measured according to the corrected optical data. Furthermore, the measuring means calculates coordinates, which represent any point in the three-dimensional space, by matching the images, which have been subjected to the coordinate transformation, with each other.
In the above measuring endoscope system, two images of an object to be inspected (object) picked up by the imaging device via the optical adaptor are subjected to coordinate transformation, and the resultant two images are matched with each other using the resultant image data items. Thus, coordinates representing any point on the object to be inspected in the three-dimensional space are calculated. Consequently, the present invention has succeeded in realizing a measuring endoscope system that is inexpensive and offers high precision in measurement.
Moreover, the measuring endoscope system is designed primarily for stereoscopic (stereo) measurement. For normal measurement, a normal optical adaptor including one optical system is detachably attached to the tip of an endoscope. An image formed by the normal optical adaptor can be used to perform normal measurement.
On the other hand, the length measuring optical adaptor for endoscopes described in the latter Japanese Unexamined Patent Application Publication No. 60-237419 is an optical adaptor that is freely detachably attached to the tip of an endoscope body and that has an index mark and a projection optical system which projects the index mark. Thus, the length measuring optical adaptor is realized as a low-cost length measuring optical adaptor. When the length measuring optical adaptor for endoscopes is attached to the endoscope body, a length measuring endoscope (measuring endoscope) is realized. Moreover, length measuring endoscopes producing different images or offering a field of view in different directions can be realized at low cost.
However, the measuring endoscope system described in the Japanese Unexamined Patent Application Publication No. 10-248806 and the length measuring optical adaptor for endoscopes described in the Japanese Unexamined Patent Application Publication No. 60-237419 have drawbacks described below.
For example, in a certain conventional measuring endoscope system, two types of optical adaptors, that is, a stereo measurement optical adaptor and a normal optical adaptor can be detachably attached to an endoscopic distal part. When the measuring endoscope system is designed to be able to perform both stereo measurement and normal measurement, a measuring program conventionally includes two routines, for example, a module for displaying an optical adaptor selection menu and prompting a user to select any of optical adaptors and a module for selecting and implementing a measuring technique optimal to the selected optical adaptor. The two modules are run independently of each other.
In other words, as far as the conventional measuring endoscope system is concerned, the optical adaptor selection menu and a measuring technique switching menu are independent of each other. Therefore, when an object to be inspected is measured, a measuring technique not associated with a selected optical adaptor maybe designated. For this reason, there is a fear that the conventional measuring endoscope system may have the performance thereof deteriorated.
Moreover, the conventional measuring endoscope system displays a menu for prompting a user to switch measuring techniques, and thus permit a user to select and implement a measuring technique. Therefore, the conventional measuring endoscope has a drawback that handling a user have to perform for measurement is so complex as to annoy the user.